1. Field of the Invention
This invention relates generally to waterbed mattresses and more specifically to that type of mattress having interior hydraulic chambers for inhibiting wave motion and for providing a controlled release of water contents.
2. Discussion of the Prior Art
Water mattresses of the past have been adapted to two general types of waterbed assemblies. In one type of assembly, upstanding hardwood side panels support the mattress which is provided with generally square corners. In another type of construction, the waterbed is provided with foam panels, commonly referred to as softwides, which extend around the perimeter of the mattress. This latter type of construction and is commonly referred to as hybrid waterbed.
Each of these types of mattresses has been constructed with an outer bladder which is adapted to contain the water. Disposed within that bladder is a hydraulic chamber assembly having multiple chambers each adapted to inhibit wave motion and to provide a controlled release of the water in the chamber. Typical of this type of construction is the water mattress disclosed in U.S. Pat. No. 4,751,756 issued to George Monzo on June 21, 1988 and entitled WATER MATTRESS WITH HYDRAULIC CHAMBER ASSEMBLY AND METHOD OF MAKING SAME.
The chambers of the past have been disposed in juxtaposition, that is, with their side walls positioned next to each other. They have been constructed generally with their top surface near the top of the bladder and the bottom surface near the bottom of the bladder. Floating foam panels have been provided in the chambers near this upper surface, and sinking weight members have been disposed near the lower surface. This has facilitated the expansion of the chambers thereby encouraging the water to enter the chambers. Holes have been provided in the walls of the chambers in both the top surface and the bottom surface in order to accommodate a flow of the water between the chambers and the bladder. Such a flow occurs when a person sits or lies on the bed and the weight of the person tends to collapse the chamber. Under these conditions the water in the chambers will gradually flow through these holes into the bladder cavity.
With this construction the chambers have tended to collapse at a uniform rate until the person is ultimately in contact with the hard wooden base which supports the bladder. From this position it is very difficult for a person to arise from the bed, as he is seated at a level typically eight inches beneath the height of the side rail. His knees are elevated to the top of the side rails and his feet are generally off of the floor.